Deposition methods for forming silicon oxide layers

ABSTRACT

A method of forming (and apparatus for forming) a metal oxide layer, preferably a dielectric layer, on a substrate, particularly a semiconductor substrate or substrate assembly, using a vapor deposition process and ozone with one or more metal organo-amine precursor compounds.

This is a continuation of application Ser. No. 11/485,105, filed Jul.12, 2006, (pending), which is a divisional of application Ser. No.10/425,514, filed Apr. 29, 2003 (now U.S. Pat. No. 7,115,528), which areall incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

This invention relates to methods of forming a layer on a substrateusing one or more metal precursor compounds and ozone during a vapordeposition process. The precursor compounds and methods are particularlysuitable for the formation of a metal oxide layer, particularly a metaloxide dielectric layer, onto a semiconductor substrate or substrateassembly.

BACKGROUND OF THE INVENTION

Capacitors are the basic energy storage devices in random access memorydevices, such as dynamic random access memory (DRAM) devices and staticrandom access memory (SRAM) devices. They consist of two conductors,such as parallel metal or polysilicon plates, which act as theelectrodes (i.e., the storage node electrode and the cell platecapacitor electrode), insulated from each other by a dielectricmaterial.

The continuous shrinkage of microelectronic devices such as capacitorsand gates over the years has led to a situation where the materialstraditionally used in integrated circuit technology are approachingtheir performance limits. Silicon (i.e., doped polysilicon) hasgenerally been the substrate of choice, and silicon dioxide (SiO₂) hasfrequently been used as the dielectric material with silicon toconstruct microelectronic devices. However, when the SiO₂ layer isthinned to 1 nm (i.e., a thickness of only 4 or 5 molecules), as isdesired in the newest micro devices, the layer no longer effectivelyperforms as an insulator due to the tunneling current running throughit.

Thus, new high dielectric constant materials are needed to extend deviceperformance. Such materials need to demonstrate high permittivity,barrier height to prevent tunneling, stability in direct contact withsilicon, and good interface quality and film morphology. Furthermore,such materials must be compatible with the gate material, semiconductorprocessing temperatures, and operating conditions.

High quality dielectric materials based on ZrO₂ and HfO₂, besidesothers, have high dielectric constants, so are being investigated asreplacements in memories for SiO₂ where very thin layers are required.These high crystalline multivalent metal oxide layers arethermodynamically stable in the presence of silicon, minimizing siliconoxidation upon thermal annealing, and appear to be compatible with metalgate electrodes.

This discovery has led to an effort to investigate various depositionprocesses to form layers, especially dielectric layers, based onzirconium and hafnium oxides and silicates. Such deposition processeshave included vapor deposition, metal thermal oxidation, and high vacuumsputtering. Vapor deposition processes, which includes chemical vapordeposition (CVD) and atomic layer deposition (ALD), are very appealingas they provide for excellent control of dielectric uniformity andthickness on a substrate.

Ritala et al., “Atomic Layer Deposition of Oxide Thin Films with MetalAlkoxides as Oxygen Sources,” SCIENCE, 288:319-321 (2000) describe achemical approach to ALD of thin oxide films. In this approach, a metalalkoxide, serving as both a metal source and an oxygen source, reactswith another metal compound such as a metal chloride or metal alkyl todeposit a metal oxide on silicon without creating an interfacial siliconoxide layer. However, undesirable chlorine residues can also be formed.Furthermore, zirconium and hafnium alkyls are generally unstable and notcommercially available. They would also likely leave carbon in theresultant films.

Despite these continual improvements in semiconductor dielectric layers,there remains a need for a vapor deposition process utilizingsufficiently volatile metal precursor compounds that can form a thin,high quality metal oxide layer, particularly on a semiconductorsubstrate using a vapor deposition process.

SUMMARY OF THE INVENTION

This invention provides, besides other things, methods of vapordepositing a metal oxide layer on a substrate. These vapor depositionmethods involve forming the layer by combining one or more metalorgano-amine precursor compounds with ozone. The invention alsoprovides, besides other things, methods of depositing a silicon oxidelayer on a substrate using an atomic layer deposition (ALD) process withone or more silicon organo-amine precursor compounds and ozone.

Significantly, the methods of the present invention do not require theuse of water or other hydrogen-producing coreactants, thus reducing (andtypically avoiding) the problem of producing a hydrogen-containinglayer.

The methods of the present invention include forming a metal oxide layeron a substrate, as occurs in a method of manufacturing a semiconductorstructure.

In certain embodiments, a method of the present invention includes:providing a substrate (preferably a semiconductor substrate or substrateassembly such as a silicon wafer); providing at least one precursorcompound of the formula M(NR¹R²)_(x)(NR³)_(y), wherein M is a metal, R¹,R², and R³ are each independently hydrogen or an organic group, x is 1or more, y is 0 or more, and the values of x and y are dependent on theoxidation state of M; providing at least one source of ozone; andcontacting the at least one precursor compound and the at least onesource of ozone to form a metal oxide layer (preferably a dielectriclayer) on one or more surfaces of the substrate using a vapor depositionprocess.

In another embodiment, a method of the present invention involves:providing a substrate (preferably a semiconductor substrate or substrateassembly such as a silicon wafer) within a deposition chamber; providinga vapor that includes at least one precursor compound of the formulaM(NR¹R²)_(x)(NR³)_(y), wherein M is a metal, R¹, R², and R³ are eachindependently hydrogen or an organic group, x is 1 or more, y is 0 ormore, and the values of x and y are dependent on the oxidation state ofM; providing a vapor that includes at least one source of ozone; andcontacting the at least one precursor compound and the at least onesource of ozone to form a metal oxide layer (preferably a dielectriclayer) on one or more surfaces of the substrate using a vapor depositionprocess.

In another embodiment, the present invention also provides a method ofmanufacturing a memory device structure, wherein the method includes:providing a substrate having a first electrode thereon; providing atleast one precursor compound of the formula M(NR¹R²)_(x)(NR³)_(y),wherein M is a metal, R¹, R², and R³ are each independently hydrogen oran organic group, x is 1 or more, y is 0 or more, and the values of xand y are dependent on the oxidation state of M; providing at least onesource of ozone; vaporizing the precursor compound to form a vaporizedprecursor compound; directing the vaporized precursor compound and theozone to the substrate to form a metal oxide dielectric layer on thefirst electrode of the substrate; and forming a second electrode on thedielectric layer. Preferably, the dielectric forms a capacitor layer,although a gate is also possible.

In an additional embodiment, the method includes providing at least oneprecursor compound of the formula M(NR¹R²)_(x)(NR³)_(y), wherein y is 0to 4, and x is 1 to 8. Preferably, y is 0, thereby providing at leastone precursor compound of the formula M(NR¹R²)_(x), wherein a value of xis dependent on the oxidation state of M. Preferably the compound offormula M(NR¹R²)_(x)(NR³)_(y) excludes silicon as M when the vapordeposition process is a chemical vapor deposition process.

In another embodiment, a method of the present invention includesforming a silicon oxide layer (typically silicon dioxide) on asubstrate. One such method includes: providing a substrate (preferably asemiconductor substrate or substrate assembly such as a silicon wafer);providing at least one precursor compound of the formulaSi(NR¹R²)_(x)Z_(y), wherein R¹ and R² are each independently hydrogen oran organic group, Z is Cl or H, x is 1 to 4, y is 0 to 4; providing atleast one source of ozone; and contacting the at least one precursorcompound and the at least one source of ozone to form a silicon oxidelayer (preferably an SiO₂ insulating layer) on one or more surfaces ofthe substrate using an atomic layer deposition process that includes aplurality of deposition cycles.

In an additional embodiment, a method of the present invention includesforming a silicon oxide layer on a substrate by providing a substrate(preferably a semiconductor substrate or substrate assembly such as asilicon wafer) within a deposition chamber; providing at least oneprecursor compound of the formula Si(NR¹R²)_(x)Z_(y), wherein R¹ and R²are each independently hydrogen or an organic group, Z is Cl or H, x is1 to 4, y is 0 to 4; providing at least one source of ozone; andcontacting the at least one precursor compound and the at least onesource of ozone to form a silicon oxide layer (preferably an SiO₂insulating layer) on one or more surfaces of the substrate within thedeposition chamber using an atomic layer deposition process thatincludes a plurality of deposition cycles.

Another method of the present invention includes a method ofmanufacturing a memory device structure with an atomic layer depositionprocess, the method includes providing a substrate having a firstelectrode thereon; providing at least one precursor compound of theformula Si(NR¹R²)_(x)Z_(y), wherein R¹ and R² are each independentlyhydrogen or an organic group, Z is Cl or H, x is 1 to 4, and y is 0 to4; providing at least one source of ozone; vaporizing the precursorcompound to form a vaporized precursor compound; directing the vaporizedprecursor compound and the ozone to the substrate to form a siliconoxide dielectric layer on the first electrode of the substrate with theatomic layer deposition process; and forming a second electrode on thedielectric layer.

The methods of the present invention can utilize a chemical vapordeposition (CVD) process, which can be pulsed, or an atomic layerdeposition (ALD) process (a self-limiting vapor deposition process thatincludes a plurality of deposition cycles, typically with purgingbetween the cycles). Preferably, the methods of the present inventionuse ALD. For certain ALD processes, the precursor compounds can bealternately introduced into a deposition chamber during each depositioncycle.

The present invention also provides a vapor deposition apparatus thatincludes: a vapor deposition chamber having a substrate positionedtherein; one or more vessels that include at least one precursorcompound of the formula M(NR¹R²)_(x)(NR³)_(y), wherein M is a metalexcept silicon, R¹, R², and R³ are each independently a hydrogen or anorganic group, x is 1 or more, y is 0 or more, and the values of x and yare dependent on the oxidation state of M; and one or more sources ofozone, such as an ozone generator that delivers an ozone oxygen mixture.

The present invention further includes an atomic layer vapor depositionapparatus that includes: a deposition chamber having a substrate(preferably a semiconductor substrate or substrate assembly such as asilicon wafer) positioned therein; one or more vessels that include atleast one precursor compound of the formula Si(NR¹R²)_(x)Z_(y), whereinR¹ and R² are each independently hydrogen or an organic group, Z is Clor H, x is 1 to 4, and y is 0 to 4; and one or more sources of ozonesuch as an ozone generator that delivers an ozone oxygen mixture.

For certain embodiments, the metal oxide layer can include an alloy, asolid solution, or a nanolaminate. For certain embodiments, the metaloxide layer can include a solid solution that includes, for example, azirconium oxide, an aluminum oxide, a tantalum oxide, a titanium oxide,a niobium oxide, a hafnium oxide, an oxide of a lanthanide, orcombinations thereof.

In an additionally preferred embodiment, a solid solution of the metaloxide layer can also include a silicon oxide (including silicates) whena silicon-containing precursor compound is provided. Thus, a solidsolution can have any combination of metal oxide layer, including asilicon oxide, if desired.

In addition, preferably the metal oxide layer is essentially free ofcarbon, nitrogen, and halogens, or compounds thereof. As used herein,“essentially free” is defined to mean that the metal oxide layer hasless than about 1% by weight of carbon, nitrogen, hydrogen, halogens, orcompounds thereof such that the presence of these elements and/orcompounds thereof having a minor effect on the chemical, mechanical, orelectrical properties of the film.

“Semiconductor substrate” or “substrate assembly” as used herein refersto a semiconductor substrate such as a base semiconductor layer or asemiconductor substrate having one or more layers, structures, orregions formed thereon. A base semiconductor layer is typically thelowest layer of silicon material on a wafer or a silicon layer depositedon another material, such as silicon on sapphire. When reference is madeto a substrate assembly, various process steps may have been previouslyused to form or define regions, junctions, various structures orfeatures, and openings such as capacitor plates or barriers forcapacitors.

“Layer” as used herein refers to any layer that can be formed on asubstrate from the precursor compounds of this invention using a vapordeposition process. The term “layer” is meant to include layers specificto the semiconductor industry, such as “barrier layer,” “dielectriclayer,” “insulating layer,” and “conductive layer.” (The term “layer” issynonymous with the term “film” frequently used in the semiconductorindustry.) The term “layer” is also meant to include layers found intechnology outside of semiconductor technology, such as coatings onglass.

“Dielectric layer” as used herein refers to a layer (or film) having ahigh dielectric constant containing primarily, for example, zirconiumoxides, aluminum oxides, tantalum oxides, titanium oxides, niobiumoxides, hafnium oxides, an oxide of a lanthanide, or combinationsthereof.

“Precursor compound” as used herein refers to an organo-amine (such asdiorganoamide (e.g., dialkylamide) or alkylimines-alkylamines) precursorcompound, for example, capable of forming a metal oxide layer on asubstrate with ozone in a vapor deposition process or a silicon dioxidelayer on a substrate with ozone in an atomic layer deposition process.The organo-amine precursor compounds are all preferably liquid at thevaporization temperature, and more preferably at room temperature. Inone example, the precursor compounds are organometallic compounds thatform volatile by-products upon reacting.

“Deposition process” and “vapor deposition process” as used herein referto a process in which a layer is formed on one or more surfaces of asubstrate (e.g., a doped polysilicon wafer) from vaporized precursorcompound(s). Specifically, one or more precursor compounds are vaporizedand directed to one or more surfaces of a heated substrate (e.g.,semiconductor substrate or substrate assembly) placed in a depositionchamber. These precursor compounds form (e.g., by reacting ordecomposing) a non-volatile, thin, uniform, layer on the surface(s) ofthe substrate. For the purposes of this invention, the term “vapordeposition process” is meant to include both chemical vapor depositionprocesses (including pulsed chemical vapor deposition processes) andatomic layer deposition processes.

“Chemical vapor deposition” (CVD) as used herein refers to a vapordeposition process wherein the desired layer is deposited on thesubstrate from vaporized metal precursor compounds (and any reactiongases used) within a deposition chamber with no effort made to separatethe reaction components. In contrast to a “simple” CVD process thatinvolves the substantial simultaneous use of the precursor compounds andany reaction gases, “pulsed” CVD alternately pulses these materials intothe deposition chamber, but does not rigorously avoid intermixing of theprecursor and reaction gas streams, as is typically done in atomic layerdeposition or ALD (discussed in greater detail below).

“Atomic layer deposition” (ALD) as used herein refers to a vapordeposition process in which numerous consecutive deposition cycles areconducted in a deposition chamber. Typically, during each cycle theprecursor compound is chemisorbed to the substrate surface; excessprecursor is purged out; a subsequent precursor and/or reaction gas isintroduced to react with the chemisorbed layer; and excess reaction gas(if used) and by-products are removed. As compared to the one cyclechemical vapor deposition (CVD) process, the longer duration multi-cycleALD process allows for improved control of layer thickness byself-limiting layer growth and minimizing detrimental gas phasereactions by separation of the reaction components. The term “atomiclayer deposition” as used herein is also meant to include the relatedterms “atomic layer epitaxy” (ALE), molecular beam epitaxy (MBE), gassource MBE, organometallic MBE, and chemical beam epitaxy when performedwith alternating pulses of precursor compound(s), reaction gas(es), andpurge (i.e., inert carrier) gas.

“Chemisorption” as used herein refers to the chemical adsorption ofvaporized reactive precursor compounds on the surface of a substrate.The adsorbed species are irreversibly bound to the substrate surface asa result of relatively strong binding forces characterized by highadsorption energies (e.g., >30 kcal/mol), comparable in strength toordinary chemical bonds. The chemisorbed species typically form amonolayer on the substrate surface. (See “The Condensed ChemicalDictionary”, 10th edition, revised by G. G. Hawley, published by VanNostrand Reinhold Co., New York, 225 (1981)). The technique of ALD isbased on the principle of the formation of a saturated monolayer ofreactive precursor molecules by chemisorption. In ALD one or moreappropriate precursor compounds or reaction gases are alternatelyintroduced (e.g., pulsed) into a deposition chamber and chemisorbed ontothe surfaces of a substrate. Each sequential introduction of a reactivecompound (e.g., one or more precursor compounds and one or more reactiongases) is typically separated by an inert carrier gas purge. Eachprecursor compound co-reaction adds a new atomic layer to previouslydeposited layers to form a cumulative solid layer. The cycle is repeatedto gradually form the desired layer thickness. It should be understoodthat ALD can alternately utilize one precursor compound, which ischemisorbed, and one reaction gas, which reacts with the chemisorbedspecies.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 are exemplary capacitor constructions.

FIG. 4 is a perspective view of a vapor deposition coating systemsuitable for use in the method of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The present invention provides, besides other things, methods of forminga metal oxide layer (preferably a metal oxide dielectric layer) on asubstrate (preferably a semiconductor substrate or substrate assembly)using one or more metal organo-amine precursor compounds with an ozonesource. The invention also provides, besides other things, methods ofdepositing a silicon oxide layer (typically a silicon dioxide layer) ona substrate using an atomic layer deposition (ALD) process. Preferably,the ALD process involves forming the silicon oxide layer by combiningone or more silicon organo-amine precursor compounds with ozone.

Preferably, the organo-amine precursor compounds include precursorcompounds having the formula M(NR¹R²)_(x)(NR³)_(y) (Formula I), whereinM is a metal, R¹, R², and R³ are each independently a hydrogen or anorganic group, x is 1 or more, y is 0 or more, and the values of x and yare dependent on the oxidation state of M. In an additional preferredembodiment, the method includes providing at least one precursorcompound of the formula M(NR¹R²)_(x)(NR³)_(y), wherein y is 0 to 4 and xis 1 to 8. Preferably, y is 0, thereby providing at least one precursorcompound of the formula M(NR¹R²)_(x) (Formula II), wherein a value of xis dependent on the oxidation state of M.

In Formulas I and II: M can be any metal (main group, transition metal,lanthanide, or metalloid (thereby including B, Al, Ge, Si, As, Sb, Te,Po, and At) although silicon is excluded for certain embodiments,particularly when used in a chemical vapor deposition process; each R(i.e., R¹, R², and R³) is independently a hydrogen or an organic group;preferably, x is 1 to 8, more preferably, x is 2 to 6; preferably, y is0 to 4, more preferably y is 0 to 2. Preferably, in Formula II, thevalue of x is 4 or 5 and the value of y is 0.

The metal oxide layer formed according to the present invention mayinclude one or more different metals and is typically of the formulaM_(n)O_(m) (Formula III), wherein M can be one or more of the metals asdefined above (i.e., the oxide can be a single metal oxide or a mixedmetal oxide). Preferably, the metal oxide layer is a single metal oxide(i.e., includes only one metal). It is possible, however, for the metaloxide layer to include two or more different metals.

If the metal oxide layer includes two or more different metals, themetal oxide layer can be in the form of alloys, solid solutions, ornanolaminates. Preferably, these have dielectric properties. The metaloxide layer (particularly if it is a dielectric layer) preferablyincludes one or more of ZrO₂, HfO₂, Ta₂O₃, Al₂O₃, Nb₂O₅, Ta₂O₅, TiO₂,and an oxide of a lanthanide.

Surprisingly, the metal oxide layer formed according to the presentinvention is essentially free of carbon, nitrogen, hydrogen, andhalogens, or compounds thereof. As used herein, “essentially free” isdefined to mean that the metal oxide layer has less than about 1% byweight of carbon, nitrogen, hydrogen, halogens, or compounds thereofsuch that the presence of these elements and/or compounds thereof haveminor effect on the chemical, mechanical, or electrical properties ofthe film.

The substrate on which the metal oxide layer is formed is preferably asemiconductor substrate or substrate assembly. Any suitablesemiconductor material is contemplated, such as for example,conductively doped polysilicon (for this invention simply referred to as“silicon”). A substrate assembly may also contain a layer that includesplatinum, iridium, rhodium, ruthenium, ruthenium oxide, titaniumnitride, tantalum nitride, tantalum-silicon-nitride, silicon dioxide,silicon nitride, aluminum, gallium arsenide, glass, etc., and otherexisting or to-be-developed materials used in semiconductorconstructions, such as dynamic random access memory (DRAM) devices andstatic random access memory (SRAM) devices, for example.

Substrates other than semiconductor substrates or substrate assembliescan be used in methods of the present invention. These include, forexample, fibers, wires, etc. If the substrate is a semiconductorsubstrate or substrate assembly, the layers can be formed directly onthe lowest semiconductor surface of the substrate, or they can be formedon any of a variety of the layers (i.e., surfaces) as in a patternedwafer, for example.

The precursor compounds described herein may include a wide variety ofmetals. As used herein, “metal” includes all metals of the periodictable (including main group metals, transition metals, lanthanides,actinides, and metalloid such as B, Al, Ge, Si, As, Sb, Te, Po, and Atbut excluding Si for certain embodiments). For certain methods of thepresent invention, preferably, each metal M is selected from the groupof metals of Group 3 (Sc, Y), Group 4 (Ti, Zr, Hf), 5 (V, Nb, Ta), Group13 (Al, Ga, In), the lanthanides (La, Ce, Pr, etc.) of the PeriodicChart, and combinations thereof. Preferably, M is selected from thegroup consisting of Al, Ti, Zr, Hf, Nb, Ta, a lanthanide (e.g., La, Ce,Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), andcombinations thereof. More preferably, M is selected from the groupconsisting of Ti, Hf, Nb, Ta, Al, Zr, and combinations thereof.

In Formula I: M is a metal selected from Group 3 (Sc, Y), Group 4 (Ti,Zr, Hf), Group 5 (V, Nb, Ta), Group 13 (Al, Ga, In), the lanthanides ofthe Periodic Table, and combinations thereof. Preferred and morepreferred metals for Formula I are as defined above.

In Formula II: M is a metal selected from Groups 3 (Sc, Y), 4 (Ti, Zr,Hf), 5 (V, Nb, Ta), the lanthanides of the Periodic Table, andcombinations thereof. Preferably, M is selected from the groupconsisting of Ti, Zr, Hf, Nb, Ta, a lanthanide (e.g., La, Ce, Pr, Nd,Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), and combinationsthereof. For certain methods of the present invention, preferably, M isselected from the group consisting of Ti, Zr, Hf, Nb, Ta, andcombinations thereof.

Preferably, the precursor compounds useful in this invention are of theformula M(NR¹R²)_(x)(NR³)_(y) (Formula I), wherein M is a metal, R¹, R²and R³ are each independently a hydrogen or an organic group (asdescribed in greater detail below), and x is 1 to 8 and y is 0 to 4,depending on the oxidation state of M. In an additional preferredembodiment, the precursor compounds useful in this invention are of theformula M(NR¹R²)_(x) (Formula II), wherein M is a metal, R¹ and R² areeach independently a hydrogen or an organic group (as described ingreater detail below), and the value of x is dependent on the oxidationstate of M, and preferably x is 4 or 5 depending on the oxidation stateof M.

For ALD processes, the metal M of the compounds of Formula I and II canfurther include all metals of the Periodic Table (including main groupmetals, transition metals, lanthanides, actinides, and metalloidsincluding Si).

For the CVD or ALD processes, organo-amine precursor compounds includeprecursor compounds having the formula Si(NR¹R²)_(x)Z_(y) (Formula III),wherein R¹ and R² are each independently hydrogen or an organic group, Zis Cl or H, x is 1 to 4, and y is 0 to 4; and precursor compounds havingthe formula Si(NR¹R²)_(x) (Formula IV), wherein R¹ and R² are eachindependently an organic group, x is 4.

As used herein, the term “organic group” is used for the purpose of thisinvention to mean a hydrocarbon group that is classified as an aliphaticgroup, cyclic group, or combination of aliphatic and cyclic groups(e.g., alkaryl and aralkyl groups). In the context of the presentinvention, suitable organic groups for precursor compounds of thisinvention are those that do not interfere with the formation of a metaloxide layer using vapor deposition techniques. In the context of thepresent invention, the term “aliphatic group” means a saturated orunsaturated linear or branched hydrocarbon group. This term is used toencompass alkyl, alkenyl, and alkynyl groups, for example. The term“alkyl group” means a saturated linear or branched monovalenthydrocarbon group including, for example, methyl, ethyl, n-propyl,isopropyl, t-butyl, amyl, heptyl, and the like. The term “alkenyl group”means an unsaturated, linear or branched monovalent hydrocarbon groupwith one or more olefinically unsaturated groups (i.e., carbon-carbondouble bonds), such as a vinyl group. The term “alkynyl group” means anunsaturated, linear or branched monovalent hydrocarbon group with one ormore carbon-carbon triple bonds. The term “cyclic group” means a closedring hydrocarbon group that is classified as an alicyclic group,aromatic group, or heterocyclic group. The term “alicyclic group” meansa cyclic hydrocarbon group having properties resembling those ofaliphatic groups. The term “aromatic group” or “aryl group” means amono- or polynuclear aromatic hydrocarbon group. The term “heterocyclicgroup” means a closed ring hydrocarbon in which one or more of the atomsin the ring is an element other than carbon (e.g., nitrogen, oxygen,sulfur, etc.).

As a means of simplifying the discussion and the recitation of certainterminology used throughout this application, the terms “group” and“moiety” are used to differentiate between chemical species that allowfor substitution or that may be substituted and those that do not soallow for substitution or may not be so substituted. Thus, when the term“group” is used to describe a chemical substituent, the describedchemical material includes the unsubstituted group and that group withnonperoxidic O, N, Si, F, or S atoms, for example, in the chain as wellas carbonyl groups or other conventional substituents. Where the term“moiety” is used to describe a chemical compound or substituent, only anunsubstituted chemical material is intended to be included. For example,the phrase “alkyl group” is intended to include not only pure open chainsaturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl,t-butyl, and the like, but also alkyl substituents bearing furthersubstituents known in the art, such as hydroxy, alkoxy, alkylsulfonyl,halogen atoms, cyano, nitro, amino, carboxyl, etc. Thus, “alkyl group”includes ether groups, haloalkyls, nitroalkyls, carboxyalkyls,hydroxyalkyls, sulfoalkyls, etc. On the other hand, the phrase “alkylmoiety” is limited to the inclusion of only pure open chain saturatedhydrocarbon alkyl substituents, such as methyl, ethyl, propyl, t-butyl,and the like.

For all the precursor compounds of this invention, each R (i.e., R¹, R²,and R³) is independently and preferably hydrogen or an organic group,more preferably a (C1-C10) organic group, even more preferably a (C1-C8)organic group, even more preferably a (C1-C6) organic group, and evenmore preferably a “lower” (i.e., C1-C4) organic group. Even morepreferably, each of these organic groups is an alkyl group. Mostpreferably, each organic group is an organic moiety, and preferably, analkyl moiety (particularly methyl and ethyl moieties).

In certain embodiments, the carbon atoms of the R groups are optionallyreplaced by or substituted with silicon (e.g., R═SiMe₃ of SiHMe₂),fluorine (e.g., fluorocarbyl groups), oxygen, and/or nitrogen atoms orgroups containing such atoms. So, the R groups can each independently beorganic groups containing silicon substituted for one or more of thecarbon atoms. Thus, silylated imine-amines and silylated amines arewithin the scope of Formulas I and II, respectively. Also, suchheteroatoms may bond to the metal, thereby forming multidentate ligands.

For the compounds of Formula I, M(NR¹R²)_(x)(NR³)_(y), each R ispreferably a (C1-C6) organic group. Examples of suitable precursorcompounds include Al(NMe₂)₂(N(Me)CH₂CH₂NMe₂) and Ta(N—^(t)Bu)(NEt₂)₃,which are either commercially available from sources such as StremChemical Co., or they can be prepared using standard techniques (e.g.,by reacting metal chlorides with the corresponding lithium dialkylamides).

For the compounds of Formula II, M(NR¹R²)_(x), each R is preferably a(C1-C6) organic group.

For hafnium precursor compounds of the formula Hf(NR¹R²)₄, R¹ and R² arepreferably both methyl, both ethyl, or one each of methyl and ethyl.Examples of suitable hafnium precursor compounds includetetrakis(dimethylamino) hafnium and tetrakis(ethylmethylamino) hafnium,the latter available from Sigma-Aldrich Chemical Co.

For zirconium precursor compounds of the formula Zr(NR¹R²)₄, R¹ and R²are preferably both methyl, both ethyl, or one each of methyl and ethyl.Examples of suitable zirconium precursor compounds includetetrakis(dimethylamino) zirconium, tetrakis(diethylamino) zirconium andtetrakis(ethylmethylamino) zirconium, all available from Sigma-AldrichChemical Co.

For the titanium precursor compounds of the formula Ti(NR¹R²)₄, R¹ andR² are preferably both methyl, both ethyl, or one each of methyl andethyl. Examples of suitable titanium precursor compounds includetetrakis(dimethylamino) titanium, tetrakis(diethylamino) titanium, andtetrakis(ethylmethylamino) titanium, all available from Sigma-AldrichChemical Co.

For the niobium precursor compounds of the formula Nb(NR¹R²)₅, R¹ and R²are preferably both methyl, both ethyl, or one each of methyl and ethyl.Examples of suitable niobium precursor compounds includepentakis(ethylmethylamino) niobium available from ATMI (Danbury, Conn.).

For the tantalum precursor compounds of the formula Ta(NR¹R²)₃(NR³), R¹and R² are preferably both methyl, both ethyl, or one each of methyl andethyl, and R³ is tert-butyl. Examples of suitable tantalum precursorcompounds include Ta(N—^(t)Bu)(NEt₂)₃ available from InorgTech(Mildenhall, Suffolk, UK).

Various precursor compounds can be used in various combinations,optionally with one or more organic solvents (particularly for CVDprocesses), to form a precursor composition. The precursor compounds maybe liquids or solids at room temperature (preferably, they are liquidsat the vaporization temperature). Typically, they are liquidssufficiently volatile to be employed using known vapor depositiontechniques. However, as solids they may also be sufficiently volatilethat they can be vaporized or sublimed from the solid state using knownvapor deposition techniques.

The precursor compounds can be vaporized in the presence of an inertcarrier gas if desired. Additionally, an inert carrier gas can be usedin purging steps in an ALD process. The inert carrier gas is typicallyselected from the group consisting of nitrogen, helium, argon, andcombinations thereof. In the context of the present invention, an inertcarrier gas is one that does not interfere with the formation of theoxide layers of the present invention.

The deposition process for this invention is a vapor deposition process.Vapor deposition processes are generally favored in the semiconductorindustry due to the process capability to quickly provide highlyconformal layers even within deep contacts and other openings. Chemicalvapor deposition (CVD) and atomic layer deposition (ALD) are two vapordeposition processes often employed to form thin, continuous, uniform,metal oxide (preferably dielectric) layers onto semiconductorsubstrates. Using either vapor deposition process, typically one or moreprecursor compounds are vaporized in a deposition chamber and optionallycombined with one or more reaction gases to form a metal oxide layeronto a substrate. It will be readily apparent to one skilled in the artthat the vapor deposition process may be enhanced by employing variousrelated techniques such as plasma assistance, photo assistance, laserassistance, as well as other techniques.

The final layer formed preferably has a thickness in the range of about10 Å to about 500 Å. Preferably, the thickness of the metal oxide layeris in the range of about 30 Å to about 100 Å.

For certain embodiments, the layer formed using the methods of thepresent invention are dielectric layers. For certain other embodiments,insulating layers are formed, particularly when silicon dioxide isformed.

For certain embodiments, the metal oxide layer can include an alloy, asolid solution, or a nanolaminate. For certain embodiments, the metaloxide layer can include a solid solution that includes, for example, azirconium oxide, an aluminum oxide, a tantalum oxide, a titanium oxide,a niobium oxide, a hafnium oxide, an oxide of a lanthanide, orcombinations thereof.

In an additionally preferred embodiment, a solid solution of the metaloxide layer can also include a silicon oxide (including silicates) whena silicon-containing precursor compound is provided. Thus, a solidsolution can have any combination of metal oxide layer, including asilicon oxide, if desired.

Chemical vapor deposition (CVD) has been extensively used for thepreparation of metal oxide layers, such as dielectric layers, insemiconductor processing because of its ability to provide highlyconformal and high quality dielectric layers at relatively fastprocessing times. The desired precursor compounds are vaporized and thenintroduced into a deposition chamber containing a heated substrate withreaction gases and/or inert carrier gases. In a typical CVD process,vaporized precursors are contacted with reaction gas(es) at thesubstrate surface to form a layer (e.g., dielectric layer). The singledeposition cycle is allowed to continue until the desired thickness ofthe layer is achieved.

Typical CVD processes generally employ precursor compounds invaporization chambers that are separated from the process chamberwherein the deposition surface or wafer is located. For example, liquidprecursor compounds are typically placed in bubblers and heated to atemperature at which they vaporize, and the vaporized liquid precursorcompound is then transported by an inert carrier gas passing over thebubbler or through the liquid precursor compound. The vapors are thenswept through a gas line to the deposition chamber for depositing alayer on substrate surface(s) therein. Many techniques have beendeveloped to precisely control this process. For example, the amount ofprecursor material transported to the deposition chamber can beprecisely controlled by the temperature of the reservoir containing theprecursor compound and by the flow of an inert carrier gas bubbledthrough or passed over the reservoir.

Preferred embodiments of the metal oxide precursor compounds describedherein are particularly suitable for chemical vapor deposition (CVD).The deposition temperature at the substrate surface is preferably heldat a temperature in a range of about 100° C. to about 600° C., morepreferably in the range of about 200° C. to about 500° C. The depositionchamber pressure is preferably maintained at a deposition pressure ofabout 0.1 torr to about 10 torr. The partial pressure of precursorcompounds in the inert carrier gas is preferably about 0.001 torr toabout 10 torr.

Several modifications of the CVD process and chambers are possible, forexample, using atmospheric pressure chemical vapor deposition, lowpressure chemical vapor deposition (LPCVD), plasma enhanced chemicalvapor deposition (PECVD), hot wall or cold wall reactors or any otherchemical vapor deposition technique. Furthermore, pulsed CVD can beused, which is similar to ALD (discussed in greater detail below) butdoes not rigorously avoid intermixing of precursor and reactant gasstreams. Also, for pulsed CVD, the deposition thickness is dependent onthe exposure time, as opposed to ALD, which is self-limiting (discussedin greater detail below).

A typical CVD process may be carried out in a chemical vapor depositionreactor, such as a deposition chamber available under the tradedesignation of 7000 from Genus, Inc. (Sunnyvale, Calif.), a depositionchamber available under the trade designation of 5000 from AppliedMaterials, Inc. (Santa Clara, Calif.), or a deposition chamber availableunder the trade designation of Prism from Novelus, Inc. (San Jose,Calif.). However, any deposition chamber suitable for performing CVD maybe used.

Alternatively, and preferably, the vapor deposition process employed inthe methods of the present invention is a multi-cycle ALD process. Morepreferably, the multi-cycle ALD process is used when the compounds ofFormula I and II include M as Si. Such a process is advantageous(particularly over a CVD process) in that in provides for optimumcontrol of atomic-level thickness and uniformity to the deposited layer(e.g., dielectric layer) and to expose the precursor compounds (bothmetal precursor compounds and silicon precursor compounds) to lowervolatilization and reaction temperatures to minimize degradation.Typically, in an ALD process, each reactant is pulsed sequentially ontoa suitable substrate, typically at deposition temperatures of about 25°C. to about 400° C. (preferably about 150° C. to about 300° C.), whichis generally lower than presently used in CVD processes. Under suchconditions the film growth is typically self-limiting (i.e., when thereactive sites on a surface are used up in an ALD process, thedeposition generally stops), insuring not only excellent conformalitybut also good large area uniformity plus simple and accurate thicknesscontrol. Due to alternate dosing of the precursor compounds and/orreaction gases, detrimental vapor-phase reactions are inherentlyeliminated, in contrast to the CVD process that is carried out bycontinuous coreaction of the precursors and/or reaction gases. (SeeVehkamäki et al, “Growth of SrTiO₃ and BaTiO₃ Thin Films by Atomic LayerDeposition,” Electrochemical and Solid-State Letters, 2(10):504-506(1999)).

A typical ALD process includes exposing an initial substrate to a firstchemical species (e.g., a precursor compound of Formulas I-IV) toaccomplish chemisorption of the species onto the substrate.Theoretically, the chemisorption forms a monolayer that is uniformly oneatom or molecule thick on the entire exposed initial substrate. In otherwords, a saturated monolayer. Practically, chemisorption might not occuron all portions of the substrate. Nevertheless, such an imperfectmonolayer is still a monolayer in the context of the present invention.In many applications, merely a substantially saturated monolayer may besuitable. A substantially saturated monolayer is one that will stillyield a deposited layer exhibiting the quality and/or properties desiredfor such layer.

The first species is purged from over the substrate and ozone isprovided to react with the first monolayer of the first species. Theozone is then purged and a second chemical species (e.g., a differentprecursor compound of Formulas I-IV) is then purged form over thesubstrate and ozone is provided to react with the monolayer of thesecond species. The steps are repeated with exposure of the firstspecies to the ozone. In some cases, the two monolayers may be of thesame species. In an additional embodiment, the ozone used in the presentinvention may be mixed with oxygen and/or with inert gases.

Purging may involve a variety of techniques including, but not limitedto, contacting the substrate and/or monolayer with a carrier gas and/orlowering pressure to below the deposition pressure to reduce theconcentration of a species contacting the substrate and/or chemisorbedspecies. Examples of carrier gases include N₂, Ar, He, etc. Purging mayinstead include contacting the substrate and/or monolayer with anysubstance that allows chemisorption by-products to desorb and reducesthe concentration of a contacting species preparatory to introducinganother species. The contacting species may be reduced to some suitableconcentration or partial pressure known to those skilled in the artbased on the specifications for the product of a particular depositionprocess.

ALD is often described as a self-limiting process, in that a finitenumber of sites exist on a substrate to which the first species may formchemical bonds. The second species might only bond to the first speciesand thus may also be self-limiting. Once all of the finite number ofsites on a substrate are bonded with a first species, the first specieswill often not bond to other of the first species already bonded withthe substrate. However, process conditions can be varied in ALD topromote such bonding and render ALD not self-limiting. Accordingly, ALDmay also encompass a species forming other than one monolayer at a timeby stacking of a species, forming a layer more than one atom or moleculethick.

The described method indicates the “substantial absence” of the secondprecursor (i.e., second species) during chemisorption of the firstprecursor since insignificant amounts of the second precursor might bepresent. According to the knowledge and the preferences of those withordinary skill in the art, a determination can be made as to thetolerable amount of second precursor and process conditions selected toachieve the substantial absence of the second precursor.

Thus, during the ALD process, numerous consecutive deposition cycles areconducted in the deposition chamber, each cycle depositing a very thinmetal oxide layer or a very thin silicon dioxide layer (usually lessthan one monolayer such that the growth rate on average is from about0.2 to about 3.0 Angstroms per cycle), until a layer of the desiredthickness is built up on the substrate of interest. The layer depositionis accomplished by alternately introducing (i.e., by pulsing) precursorcompounds into the deposition chamber containing a semiconductorsubstrate, chemisorbing the precursor compound(s) as a monolayer ontothe substrate surfaces, and then reacting the chemisorbed precursorcompound(s) with ozone. The pulse duration of precursor compound(s) andinert carrier gas(es) is sufficient to saturate the substrate surface.Typically, the pulse duration is from about 0.1 to about 5 seconds,preferably from about 0.2 to about 1 second.

In comparison to the predominantly thermally driven CVD, ALD ispredominantly chemically driven. Accordingly, ALD is often conducted atmuch lower temperatures than CVD. During the ALD process, the substratetemperature is maintained at a temperature sufficiently low to maintainintact bonds between the chemisorbed precursor compound(s) and theunderlying substrate surface and to prevent decomposition of theprecursor compound(s). The temperature is also sufficiently high toavoid condensation of the precursor compounds(s). Typically thesubstrate temperature is kept within the range of about 25° C. to about400° C. (preferably about 150° C. to about 300° C.), which is generallylower than presently used in CVD processes. Thus, the first species orprecursor compound is chemisorbed at this temperature. Surface reactionof the precursor compound can occur at substantially the sametemperature as chemisorption of the precursor or, less preferably, at asubstantially different temperature. Clearly, some small variation intemperature, as judged by those of ordinary skill, can occur but stillbe a substantially same temperature by providing a reaction ratestatistically the same as would occur at the temperature of theprecursor chemisorption. Chemisorption and subsequent reactions couldinstead occur at exactly the same temperature.

For a typical ALD process, the pressure inside the deposition chamber iskept at about 10⁻⁴ torr to about 1 torr, preferably about 10⁻⁴ torr toabout 0.1 torr. Typically, the deposition chamber is purged with aninert carrier gas after the vaporized precursor compound(s) have beenintroduced into the chamber and/or reacted for each cycle. The inertcarrier gas(es) can also be introduced with the vaporized precursorcompound(s) during each cycle.

The reactivity of a precursor compound can significantly influence theprocess parameters in ALD. Under typical CVD process conditions, ahighly reactive compound may react in the gas phase generatingparticulates, depositing prematurely on undesired surfaces, producingpoor films, and/or yielding poor step coverage or otherwise yieldingnon-uniform deposition. For at least such reason, a highly reactivecompound might be considered not suitable for CVD. However, somecompounds not suitable for CVD are superior ALD precursors. For example,if the first precursor is gas phase reactive with the second precursor,such a combination of compounds might not be suitable for CVD, althoughthey could be used in ALD. In the CVD context, concern might also existregarding sticking coefficients and surface mobility, as known to thoseskilled in the art, when using highly gas-phase reactive precursors,however, little or no such concern would exist in the ALD context.

After layer formation on the substrate, an annealing process can beoptionally performed in situ in the deposition chamber in a nitrogenatmosphere or oxidizing atmosphere. Preferably, the annealingtemperature is within the range of about 400° C. to about 1000° C.Particularly after ALD, the annealing temperature is more preferablyabout 400° C. to about 750° C., and most preferably about 600° C. toabout 700° C. Alternatively, the annealing process can also includeannealing in a plasma. The annealing operation is preferably performedfor a time period of about 0.5 minute to about 60 minutes and morepreferably for a time period of about 1 minute to about 10 minutes. Oneskilled in the art will recognize that such temperatures and timeperiods may vary. For example, furnace anneals and rapid thermalannealing may be used, and further, such anneals may be performed in oneor more annealing steps.

As stated above, the use of the complexes and methods of forming filmsof the present invention are beneficial for a wide variety of thin filmapplications in semiconductor structures, particularly those using highdielectric materials. For example, such applications include capacitorssuch as planar cells, trench cells (e.g., double sidewall trenchcapacitors), stacked cells (e.g., crown, V-cell, delta cell,multi-fingered, or cylindrical container stacked capacitors), as well asfield effect transistor devices. Thus, for certain embodiments, thedielectric layer forms a capacitor layer. Alternatively, the dielectriclayer forms a gate.

A specific example of where a dielectric layer is formed according tothe present invention is a capacitor construction. Exemplary capacitorconstructions are described with reference to FIGS. 1-3. Referring toFIG. 1, a semiconductor wafer fragment 10 includes a capacitorconstruction 25 formed by a method of the present invention. Waferfragment 10 includes a substrate 12 having a conductive diffusion area14 formed therein. Substrate 12 can include, for example,monocrystalline silicon. An insulating layer 16, typicallyborophosphosilicate glass (BPSG), is provided over substrate 12, with acontact opening 18 provided therein to diffusion area 14. A conductivematerial 20 fills contact opening 18, with material 20 and oxide layer18 having been planarized as shown. Material 20 might be any suitableconductive material, such as, for example, tungsten or conductivelydoped polysilicon. Capacitor construction 25 is provided atop layer 16and plug 20, and electrically connected to node 14 through plug 20.

Capacitor construction 25 includes a first capacitor electrode 26, whichhas been provided and patterned over node 20. Exemplary materialsinclude conductively doped polysilicon, Pt, Ir, Rh, Ru, RuO₂, IrO₂,RhO₂. A capacitor dielectric layer 28 is provided over first capacitorelectrode 26. The materials of the present invention can be used to formthe capacitor dielectric layer 28. Preferably, if first capacitorelectrode 26 includes polysilicon, a surface of the polysilicon iscleaned by an in situ HF dip prior to deposition of the dielectricmaterial. An exemplary thickness for layer 28 in accordance with 256 Mbintegration is 100 Angstroms.

A diffusion barrier layer 30 is provided over dielectric layer 28.Diffusion barrier layer 30 includes conductive materials such as TiN,TaN, metal silicide, or metal silicide-nitride, and can be provided byCVD, for example, using conditions well known to those of skill in theart. After formation of barrier layer 30, a second capacitor electrode32 is formed over barrier layer 30 to complete construction of capacitor25. Second capacitor electrode 32 can include constructions similar tothose discussed above regarding the first capacitor electrode 26, andcan accordingly include, for example, conductively doped polysilicon.Diffusion barrier layer 30 preferably prevents components (e.g., oxygen)from diffusing from dielectric material 28 into electrode 32. If, forexample, oxygen diffuses into a silicon-containing electrode 32, it canundesirably form SiO₂, which will significantly reduce the capacitanceof capacitor 25. Diffusion barrier layer 30 can also prevent diffusionof silicon from metal electrode 32 to dielectric layer 28.

FIG. 2 illustrates an alternative embodiment of a capacitorconstruction. Like numerals from FIG. 1 have been utilized whereappropriate, with differences indicated by the suffix “a”. Waferfragment 10 a includes a capacitor construction 25 a differing from theconstruction 25 of FIG. 2 in provision of a barrier layer 30 a betweenfirst electrode 26 and dielectric layer 28, rather than betweendielectric layer 28 and second capacitor electrode 32. Barrier layer 30a can include constructions identical to those discussed above withreference to FIG. 1.

FIG. 3 illustrates yet another alternative embodiment of a capacitorconstruction. Like numerals from FIG. 1 are utilized where appropriate,with differences being indicated by the suffix “b” or by differentnumerals. Wafer fragment 10 b includes a capacitor construction 25 bhaving the first and second capacitor plate 26 and 32, respectively, ofthe first described embodiment. However, wafer fragment 10 b differsfrom wafer fragment 10 of FIG. 2 in that wafer fragment 10 b includes asecond barrier layer 40 in addition to the barrier layer 30. Barrierlayer 40 is provided between first capacitor electrode 26 and dielectriclayer 28, whereas barrier layer 30 is between second capacitor electrode32 and dielectric layer 28. Barrier layer 40 can be formed by methodsidentical to those discussed above with reference to FIG. 1 forformation of the barrier layer 30.

In the embodiments of FIGS. 1-3, the barrier layers are shown anddescribed as being distinct layers separate from the capacitorelectrodes. It is to be understood, however, that the barrier layers caninclude conductive materials and can accordingly, in such embodiments,be understood to include at least a portion of the capacitor electrodes.In particular embodiments an entirety of a capacitor electrode caninclude conductive barrier layer materials.

A system that can be used to perform vapor deposition processes(chemical vapor deposition or atomic layer deposition) of the presentinvention is shown in FIG. 4. The system includes an enclosed vapordeposition chamber 110, in which a vacuum may be created using turbopump 112 and backing pump 114. One or more substrates 116 (e.g.,semiconductor substrates or substrate assemblies) are positioned inchamber 110. A constant nominal temperature is established for substrate116, which can vary depending on the process used. Substrate 116 may beheated, for example, by an electrical resistance heater 118 on whichsubstrate 116 is mounted. Other known methods of heating the substratemay also be utilized.

In this process, precursor compounds 160 (e.g., a refractory metalprecursor compound and an ether) are stored in vessels 162. Theprecursor compounds are vaporized and separately fed along lines 164 and166 to the deposition chamber 110 using, for example, an inert carriergas 168. A reaction gas 170 may be supplied along line 172 as needed.Also, a purge gas 174, which is often the same as the inert carrier gas168, may be supplied along line 176 as needed. As shown, a series ofvalves 180-185 are opened and closed as required.

The following examples are offered to further illustrate the variousspecific and preferred embodiments and techniques. It should beunderstood, however, that many variations and modifications may be madewhile remaining within the scope of the present invention, so the scopeof the invention is not intended to be limited by the examples. Unlessspecified otherwise, all percentages shown in the examples arepercentages by weight.

EXAMPLE Example 1 Atomic Layer Deposition of HfO₂

Using an ALD process, precursor compounds hafnium dimethylamide,Hf(N(CH₃)₂)₄ (Strem Chemicals, Newbury Port, Mass.), and an ozone/oxygen(O₃/O₂) mixture, having approximately 10% ozone by weight, werealternately pulsed for 600 cycles into a deposition chamber containing aBPSG substrate. A 590 Å layer of HfO₂ was deposited, containing 37 atom% Hf, and 63 atom % oxygen. The layer of HfO₂ was, surprisingly, free ofcarbon and nitrogen within detection limits of XPS at a substratetemperature of approximately 220° C.

The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. Variousmodifications and alterations to this invention will become apparent tothose skilled in the art without departing from the scope and spirit ofthis invention. It should be understood that this invention is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the inventionintended to be limited only by the claims set forth herein as follows.

1. A vapor deposition method comprising: providing a vapor comprising atleast one precursor compound consisting of the formulaSi(NR¹R²)_(x)Z_(y), wherein: R¹ and R² are each independently hydrogenor an organic group; Z is Cl or H; x is 1 to 4; and y is 0 to 4;providing at least one source of ozone; and contacting the vaporscomprising the at least one precursor compound and the at least onesource of ozone with a substrate to form a silicon oxide layer on one ormore surfaces of the substrate using an atomic layer deposition processcomprising a plurality of deposition cycles.
 2. The method of claim 1wherein R¹ and R² are each independently hydrogen or organic groupshaving 1-10 carbon atoms.
 3. The method of claim 1 wherein R¹ and R² areeach independently organic groups having silicon substituted for one ormore carbon atoms.
 4. The method of claim 1 wherein R¹ and R² are eachindependently hydrogen or a (C1-C8)alkyl moiety.
 5. The method of claim1 wherein R¹ and R² are each independently selected from the groupconsisting of methyl and ethyl moieties.
 6. The method of claim 1wherein y is 0 and x is 4, thereby providing at least one precursorcompound of the formula Si(NR¹R²)₄.
 7. A vapor deposition methodcomprising: contacting a vapor comprising at least one precursorcompound with a substrate and allowing the at least one precursorcompound to chemisorb on the surface of the substrate, wherein the atleast one precursor compound consists of the formula Si(NR¹R²)_(x)Z_(y),wherein: R¹ and R² are each independently hydrogen or an organic group;Z is Cl or H; x is 1 to 4; and y is 0 to 4; and contacting a vaporcomprising at least one source of ozone with the substrate having the atleast one precursor compound chemisorbed thereon to form a silicon oxidelayer, wherein contacting comprises an atomic layer deposition processcomprising a plurality of deposition cycles.
 8. The method of claim 7wherein the silicon oxide layer is essentially free of carbon, nitrogen,halogens, and compounds thereof.
 9. The method of claim 7 wherein thesilicon oxide layer is an SiO₂ insulating layer.
 10. The method of claim7 wherein the silicon oxide layer is in the form of an alloy, a solidsolution, or a nanolaminate.
 11. The method of claim 7 wherein thesilicon oxide layer has a thickness of about 30 Å to about 100 Å.
 12. Amethod of making a semiconductor structure, the method comprising:providing a semiconductor substrate or substrate assembly within adeposition chamber; providing a vapor comprising at least one precursorcompound consisting of the formula Si(NR¹R²)_(x)Z_(y), wherein: R¹ andR² are each independently hydrogen or an organic group; Z is Cl or H; xis 1 to 4; and y is 0 to 4; directing the vapor comprising the at leastone precursor compound to one or more surfaces of the semiconductorsubstrate or substrate assembly within the deposition chamber; providinga vapor comprising at least one source of ozone; and directing the atleast one source of ozone to the one or more surfaces of thesemiconductor substrate or substrate assembly within the depositionchamber to form a silicon oxide layer, wherein providing the vapors anddirecting the vapors is accomplished using an atomic layer depositionprocess comprising a plurality of deposition cycles.
 13. The method ofclaim 12 wherein the semiconductor substrate or substrate assembly is asilicon wafer.
 14. The method of claim 12 wherein R¹ and R² are eachindependently selected from the group consisting of methyl and ethylmoieties.
 15. The method of claim 12 wherein the silicon oxide layer isan SiO₂ insulating layer.
 16. The method of claim 12 wherein the siliconoxide layer has a thickness of about 30 Å to about 100 Å.
 17. A methodof making a semiconductor structure, the method comprising: positioninga semiconductor substrate or substrate assembly within a depositionchamber; contacting a vapor comprising at least one precursor compoundwith the semiconductor substrate or substrate assembly and allowing theat least one precursor compound to chemisorb on the surface thereof,wherein the at least one precursor compound consists of the formulaSi(NR¹R²)_(x)Z_(y), wherein: R¹ and R² are each independently hydrogenor an organic group; Z is Cl or H; x is 1 to 4; and y is 0 to 4; purgingexcess precursor compound from the deposition chamber using an inertgas; contacting a vapor comprising at least one source of ozone with thesubstrate having the at least one precursor compound chemisorbedthereon; and purging excess ozone from the deposition chamber using aninert gas, wherein contacting and purging is accomplished using anatomic layer deposition process comprising a plurality of depositioncycles to form a silicon oxide layer.
 18. The method of claim 17 whereinthe at least one precursor compound is directed to the semiconductorsubstrate or substrate assembly in the presence of an inert carrier gas.19. The method of claim 17 wherein during the atomic layer depositionprocess the silicon oxide layer is formed by alternately introducing theat least one precursor compound and the at least one source of ozoneduring each deposition cycle.
 20. The method of claim 17 wherein thetemperature of the semiconductor substrate or substrate assembly isabout 25° C. to about 400° C.